Note: Descriptions are shown in the official language in which they were submitted.
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ROLL-FORMING APPARATUS FOR ~:
CONTINUOUS OR INTERLEAVED WEBS
Te- hni~l Field
The present invention relates generally to a winding and roll-
forming apparatus for forming rolls of material from associated continuous or
interleaved webs, and more particularly to a high-speed roll-forming
apparatus including improved drive systems for indexing and driving the
spindles of the apparatus upon which rolls of material are formed.
l~ k~- ~d Of The Invention
In order to form individual rolls of continuous or interleaved
webs of material, winding and roll-forming devices are known which are
configured to receive endless webs of material, effect separation into
continuous or interleaved webs, and subsequent rolling of the webs into
individual rolls. These types of devices are advantageously employed for
h~n-llinp webs of material in the forms of plastic bags or the like, and can be
operated to form continuous webs with the bags (or other like elements)
joined end-to-end, or webs in which the bags are separated (at suitable
perforations) into discrete elements, and interleaved to form a web.
In a typical roll-forming apparatus of the above type, one or
more conveyor assemblies effect formation of the continuous or interleaved
webs, with an intermittently indexed turret assembly employed for formation
of each web into an individual roll. The turret assembly includes a plurality
of rotatable roll-forming spindles mounted thereon, with the apparatus
configured to direct each web onto a respective one of the spindles, which
are then rotatably driven so that the web of material is rolled thereabout. As
the turret assembly is indexed, successive ones of the spindles are positioned
for respectively receiving successive ones of the webs of material.
Upon completion of the rolling of each web of material on a
respective one of the driven spindles, the turret assembly is indexed to
present the completed roll to a push-off mech~ni.~m, which slides the
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completed roll off of the respective spindle. Continue~l indexing of the turret
assembly again positions that spindle for receiving another web of material,
and the cycle repeated in a like fashion. The rolls can be formed directly on
the spindle, or on cores placed on the spindle prior to starting a new roll.
While machines of the above type have been in widespread use,
~ certain operating aspects of these devices, including the drive for the roll-
forming spindles, have been less than optimal. In the past, magnetic clutch
assemblies have been employed for effecting driving of each spindle during
transfer of a web of material thereto for initiation of roll-forming, and duringwinding of the web of material thereon. However, experience has shown that
these m~gnetic clutch assemblies do not always provide the desired service
life, and can be subject to inconsistent operation due to temperature
fluctuations and changes in line speed.
In previous machines, indexing movement of the turret
assembly has been effected through a mechanical drive train connected to the
conveyor which supplies webs of material to the roll-forming spindles. As
such, the turret rotates at a speed proportional to the line speed. However,
such an arrangement does not offer the desired level of versatility required
for optimal h~n-lling of various types of material under varying h~nrlling
conditions.
As noted, removal of a completed roll of material is effected by
a push-off mechanism which engages the completed roll as the turret is
indexed to present the associated spindle. This push-off mechanism displaces
the rolled material axially of the spindle, but for certain materials (such as
low density plastic film) the completed roll undesirably tends to adhere to the
spindle. While attempts have been made to provide lubricant on the surface
of each spindle, such lubricant can be messy, and can inhibit the desired
adherence of the web material to each spindle during roll formation (i.e., the
spindle spins freely inside of the roll).
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The present invention is directed to a roll-forming apparatus
which provides improved pe~ro-nlance over previously known constructions
for enh~nred versatility, reliability and operating efficiency.
S~lmm~ry Of The Invention
A roll-forming apparatus embodying the principles of the
present invention has been specifically configured for enh~nce(l efficiency and
versatility in the formation of rolls from elongated webs of material, which
may be either continuous, or comprise interleaved discrete elements. The
apparatus includes improved drive arrangements for roll-forming spindles of
the apparatus, including a spindle-reversing drive for facilit~ting removal of
completed rolls. Additionally, a spindle-supporting turret of the apparatus is
provided with an inle,lllillent drive arrangement, separate from other drive
systems of the apparatus, thereby further enhancing the efficiency of the
apparatus under varying operating conditions, and for e~h~n~-ed versatility in
the h~n~ling of different types of material.
In accordance with the illustrated embodiment, the present roll-
forming apparatus is configured for forming individual rolls of material from
associated webs of the material. The apparatus includes a conveyor for
sequentially receiving the associated webs, and a conveyor drive operatively
connected to the conveyor for continuously driving the conveyor, and for
continuously advancing each web of material through the conveyor.
The apparatus includes a turret assembly positioned
downstream of the conveyor for sequentially receiving the webs of material
therefrom. The turret assembly includes a rotatable turret having a plurality
of roll-forming spindles mounted thereon. Each of the spindles is rotatable
relative to the turret, with the turret being configured for intermittent,
indexed rotation so that the spindles are successively presented to receive
respective ones of the webs of material thereon for formation of the rolls.
In order to facilitate efficient and consislel1t transfer of each
web of material from the conveyor to its respective spindle, the apparatus
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includes a transfer drive which drives one of the spindles (i.e., the transfer
spindle) at substantially the same speed as the conveyor, as a leading edge of
one of the webs of material is transferred onto that one of the spindles. In
the pler~lled embodiment, the transfer drive is mechanically driven by the
conveyor drive, thus assuring that the surface speed of the spindle is the same
as the speed of the conveyor which transfers the web of material to the
spindle. Alternately, a speed-adjustable electric motor may be employed for
driving the spindle onto which the web of material is transferred, with the
electric motor adjusted to provide a spindle surface speed equal to the
conveyor speed.
Further versatility is achieved by the provision of a winding
drive which effects driven rotation of each spindle after a respective one of
the webs of material has been transferred thereto (referred to as the winding
spindle). In a presently preferred construction, the winding drive comprises
a torque-controlled electric motor, the output of which can be selectively
varied as the roll of material is formed on the associated spindle. In the
illustrated embodiment, an arrangement is provided for measuring the
diameter of the roll as it is formed on each spindle, with a control
arrangement provided for selectively varying the torque output of the winding
drive motor in relation to the diameter of the roll of material being formed.
In the preferred embodiment, the drive for driving each spindle
during web transfer comprises a transfer drive belt, and the drive for
effecting roll winding on each spindle comprises a winding drive belt. The
arrangement of the drive belts is such that as each spindle is moved from a
transfer position to a winding position by indexing movement of the
associated turret, each spindle is moved out of driven engagement with the
transfer drive belt and into driven engagement with the winding drive belt.
This desirably straightforward drive arrangement obviates the need for
driving the spindles with the typical externally toothed timing belts, and thus,each spindle preferably comprises a non-toothed driven surface (either
CA 0220~79~ 1997-0~-22
smooth or knurled) engageable with the transfer and winding drive belts.
Additionally, indexed movement of the turret assembly is effected by the
provision of a servo-controlled electric motor, thus providing the necess~ry
inle~ lent rotation of the turret assembly independently of other drive
systems of the apparatus. The speed of rotation of the turret is adjustable to
aCcommo~l~te different materials or operating modes.
Upon completion of roll-formation, indexing movement of the
turret assembly presents the completed roll to a push-off mech~ni~m.
Notably, the present apparatus preferably includes an arrangement for driving
each spindle in a direction opposite to that in which it is rotated during roll-formation, to thereby facilitate removal of the roll of material from the
spindle. Thus, at the push-off position of each spindle, the spindle is briefly
driven in a reverse direction, thus slightly "unscrewing" the roll of material
prior to its axial displacement from the spindle by the push-off mech~ni.~m
Other features and advantages of the present invention will
become readily apparent from the following detailed description, the
accompanying drawings, and the appended claims.
Brief Des~ lion Of The Drawings
PIGURE 1 is a diagr~mm~tic view of a roll-forming apparatus
embodying the principles of the present invention, shown as a front
elevational view of a left-hand m~ç~ine;
FIGURE 2 is a side-elevational view, similar to FIGURE 1,
shown as a back view of a left-hand machine, further illustrating the present
roll-forming apparatus with certain components being admitted for clarity of
illustration;
FIGURE 3 is a further side-elevational view of the present
apparatus, shown as a back view of a left-hand m~rhinP, again with certain
components omitted for clarity of illustration; and
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FIGURE 4 is a diagr~mm~tic view, shown as a back view of a
left-hand m~chinP, illustrating a drive arrangement for a turret assembly of
the present roll-forming apparatus.
Detail Des~ tion
While the present invention is susceptible of embodiment in
various forms, there is shown in the drawings and will hereinafter be
described a presently preferred embodiment, with the understanding that the
present disclosure is to be considered as an exemplification of the invention,
and is not intended to limit the invention to the specific embodiment
illustrated.
With reference to FIGURE 1, therein is illustrated a winding or
roll-forming apparatus 10 embodying the principles of the present invention.
Many of the specific details of the present apparatus will be well-known to
those f~mili~r with the art, and thus, such details are omitted for clarity. As
will be recognized, apparatus 10 is configured generally in accordance with
U.S. Patent No. 5,197,727, to Lotto et al., hereby incorporated by reference,
and as such, the apparatus is configured to form individual rolls of material
from elongated webs of material at high speed. In a typical application, each
web of material comprises a plurality of elements, such as bags. For
purposes of the present disclosure, reference to continuous webs of material
contemplates those webs which may include individual elements joined in
end-to-end relation, such as by perforated portions. In contrast, the present
apparatus can be employed for h~n~lling webs of material which comprise a
plurality of discrete, interleaved elements. For either application, the webs
of material are formed from an endless web supplied to the apparatus.
While the present apparatus will be described in connection
with roll-formation of elongated webs of bags or like elements, it is within
the purview of the present invention that the present winding apparatus can
be configured for roll-formation of a wide variety of goods, including folded
banners, signs, bumper stickers, pre-cut tape segments, tubes of plastic or
CA 0220~79~ 1997-0~-22
other material, woven products such as pre-cut bandages, as well as bags of
widely varying sizes.
Roll-forming apparatus 10 includes a frame 12 which carries an
infeed conveyor 14, a slow-down conveyor 16 positioned dowlls~leam
5 thereof, and a turret assembly 18 positioned downstream of the conveyor 16.
The turret assembly includes a rotatable turret 19 driven for intermittent,
indexed rotation, and a plurality of spindles 20, respectively designated 20a,
20b, 20c, 20d, with respect to the indexed positions of the spindles. In
-particular, spindle 20a is positioned for transfer of a web of material from
slow-down conveyor 16, and thus, is referred to as the transfer spindle.
After transfer is effected, the spindle is rotatably indexed (clockwise,
referring to the orientation of FIGURE 1) to position of spindle 20b, where
driven rotation of the spindle effects winding of the web of material, and roll-formation. Thus, the spindle in the position of 20b is the so-called winding
spindle. After completion of roll-formation, indexing rotation of turret 19
positions each spindle in the position of spindle 20c, at which push-off of the
completed roll is effected. After removal of the roll from the spindle, each
spindle is positioned in an inactive position, represented by spindle 20d, priorto further indexing of each spindle to the position of spindle 20a for effectingweb transfer.
With reference now to FIGURE 1, the sequence of operation of
apparatus 10 will be described. With flow of material through the apparatus,
generally taking place in a right-to-left direction, referring to the orientation
of FIGURE 1, an endless web of material is first received by infeed conveyor
14 between a pair of opposed infeed nip rolls 26. The endless web of
material is directed from nip rolls 26 to a pair of opposed separator rolls 28,
which can be selectively moved toward each other for operative engagement
with the endless web. Separator rolls 28 are operated at a peripheral speed
greater than the peripheral speed of infeed nip rolls 26, with engagement of
the separator rolls with the endless web effecting subdivision of the web. If
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continuous webs of material (such as end-to-end bags) are to be formed,
separator rolls 28 are operated so as to separate each ~connected" web of
material from the endless web being supplied to the apparatus. Perforations
in the endless web, such as between the individual bags or other elements,
S facilitate separation of the webs of material, which are then directed through
the apparatus to slow-down conveyor 16.
For many applications, it is desired that a web of material be
formed having discrete, individual interleaved elements. For formation of
~ interleaved webs, separator rolls 28 are operated so as to separate each
element (as by tearing of the perforations in the web) from the adjacent ones
of the elements in the endless web supplied to the apparatus. Depending
upon the type of material being conveyed, the infeed conveyor 14 may
include one or more upper and lower conveyor belts or relatively narrow
"ropes", with the infeed conveyor driven by an associated infeed conveyor
drive 32.
Interleaving of the individual bags or other elements to form an
interleaved web is effected as the material is moved from infeed conveyor 14
to slow-down conveyor 16. The slow-down conveyor 16 includes a pair of
opposed slow-down nip rolls 36 at the upstream end of the conveyor, with a
nose roll 38 positioned at the downstream end of the conveyor for
cooperation with winding spindle 20b, as will be further described. Like the
infeed conveyor, slow-down conveyor 16 may include one or more upper and
lower conveyor belts or ropes 40 for conveyance of the web material
therethrough.
Interleaving of individual elements is effected by the provision
of a blow-down tube 42, a blow-up tube 44, and a vacuum box 46.
Interleaving (i.e., overlapping of the discrete elements) is effected by
operating the slow-down conveyor 16 at a speed slower than infeed conveyor
14. The speed differential between the conveyors provides the desired degree
of interleaving.
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Interleaving is effected during transfer of a discrete web
element from conveyor 14 to conveyor 16. As the leading edge of the web
element is received between slow-down nip rolls 36, blow-down tube 42 is
operated to direct pressurized air against the upper surface of the web
element. In view of the speed differential between the infeed and slow-down
conveyors, slack created in the web element results in a trailing portion of
the element moving downwardly under the influence of the air from blow-
down tube 42. As the trailing end of the element is released from infeed
conveyor 14, pressurized air from blow-down tube 42 urges the trailing
portion of the element onto vacuum box 46. The vacuum box includes a
foraminous surface which acts to hold the trailing portion of the web element
in sliding disposition on the vacuum box.
Slow-down conveyor nip rolls 36 continue to draw the web
element into the slow-down conveyor, even as it is held dowllw~rdly by the
vacuum box 46. Concurrently, the next successive web element is being
moved out of infeed conveyor 14 toward the slow-down conveyor 16.
Because the trailing portion of the previous web element is held downwardly
on vacuum box 46, and by virtue of the speed differential of the infeed and
slow-down conveyors, overlapping or interleaving of the leading and trailing
portions of the successive web elements is effected. The desired interleaving
is enhanced by direction of pressurized air from blow-up tube 44 against the
lower surface of the leading portion of the successive web element, with the
flow of air from blow-down tube 42 interrupted. As the overlapped portions
of the successive web elements are drawn into slow-down nip rolls 36, the
cycle of interleaving is repeated through the coordinated action of blow-down
tube 42, vacuum box 46, and blow-up tube 44.
One feature of the present apparatus which provides enh~n~ed
versatility in comparison to previous arrangements is the provision of a
separate conveyor drive 48 (FIGURE 2) for the slow-down conveyor 16.
Rather than provide a single drive for all components of the present
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- 10-
apparatus, the provision of a separate conveyor drive 48 for the slow-down
conveyor permits the degree of interleaving of the discrete web elements to
be readily selectively varied. In a current embodiment, conveyor drive 48
comprises a speed-adjustable electric motor, preferably comprising a variable
frequency AC drive such as comprising a Saftronics Model No. PCU40P701,
available from Saftronics of Fort Meyers, Florida, and a standard AC
induction motor. The reference speed input to the variable frequency AC
drive is selected by a relay that is controlled by an associated programmable
logic controller of the apparatus, a General Electric/Fanuc Series 90-30.
When the selector switch of the controller is turned to the "interleaf mode",
the speed reference comes from a potentiometer mounted on the operator
panel. The amount of interleaf is controlled by the potentiometer by dialing
down the speed of the variable frequency AC drive, and therefore the speed
of the slow-down conveyor. This adjustment arrangement is infinitely
variable for selecting the degree of interleaving of the web elements.
When continuous webs of material (without interleaved discrete
elements) are being handled by the apparatus, the logic controller switches a
relay so that the slow-down conveyor drive 48 gets its speed reference from
the infeed conveyor drive 32 through an output on the infeed drive which is
proportional to its speed. The infeed drive 32 may include components as
those described above for the slow-down conveyor drive. By this
arrangement, the slow-down conveyor drive 32 follows the infeed drive
exactly, or can be offset slightly through drive parameter settings, a fraction
of a percent or higher or lower. This speed differential can be desirable for
some specific film composition or thickness applications, but is ordinarily not
necess~ry. While the use of variable frequency AC drives is presently
preferred, it is to be understood that other types of drives capable of being
coordinated within one-tenth of one percent could be alternately employed.
With further reference to FIGURE 1, transfer of the leading
edge of each web of material from the slow-down conveyor 16 to the transfer
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spindle 20a is effected by the cooperating action of a movable air horn 52,
and a movable kick roll 54. The spindle 20a (i.e., the transfer spindle) is
positioned as shown, with indexed rotation of turret 19 stopped so that the
spindle is held in position. As will be further described, the spindle 20a is
driven to rotate at a speed which is the same as the speed of the slow-down
conveyor 16, thus facilit~ting transfer of the leading edge of a web of
material to the transfer spindle. For most applications, it is desirable to
provide each of the spindles 20 with suitable vacuum openings through which
a vacuum is drawn when each spindle is positioned for kansfer of material
from slow-down conveyor 16.
In order to effect transfer of the leading edge of the web of
material from the slow-down conveyor 16 to the transfer spindle 28, the air
horn 52 is rotated to a position to generally cover the transfer spindle. When
the leading edge of the web of material is just approa~lling the air horn, the
kick roll 54 is moved upwardly to urge the conveyor belt 40 of the slow-
down conveyor 16 upwardly toward the transfer spindle 20a. At the same
time, pressurized air is directed from the air horn onto the conveyor belt,
thereby blowing the leading edge of the web of material generally upwardly
onto the transfer spindle, with the vacuum drawn therethrough facilit~ting
gripping of the leading edge of the web. Driven rotation of the transfer
spindle effects initiation of roll-formation, with subsequent indexing
movement of the turret 19 moving the transfer spindle to the winding spindle
position for winding of the web of material received from slow-down
conveyor 16.
With particular reference to FIGURES 2 and 3, the ~lcsellt
invention employs a drive arrangement for the transfer spindle which acts to
drive the spindle at substantially the same speed as the slow-down conveyor,
as the leading edge of the web of material is transferred onto the spindle.
While it is presently preferred that the transfer spindle be driven at the same
speed as the slow-down conveyor, some applications may call for the speed
CA 0220~79~ 1997-0~-22
of the spindle to vary slightly from the conveyor speed. In the presently
preferred embodiment, this drive arrangement for the transfer spindle
comprises a transfer drive belt 56 driven via a jackshaft 58 and an
interm~di~te drive belt 60, which in turn are driven by the slow-down
conveyor drive 48. Thus, the speed of transfer drive belt 56 is directly
proportional to the speed of conveyor drive 48, thus effecting coordination of
the speed of the transfer spindle with the speed of the slow-down conveyor
16. As illustrated in FIGURE 3, the transfer spindle 20a is in driven
engagement with the transfer drive belt 56 when the spindle is in the transfer
position.
While driven rotation of the transfer spindle is preferably
effected mPçll~nic~lly from the conveyor drive 48, it is within the purview of
the present invention to instead provide a speed-adjustable motor for effecting
driven rotation of the transfer spindle. This can be effected by the use of a
variable frequency AC drive system, operated to control the speed of the
transfer spindle by following the speed of the slow-down conveyor 16.
Again, it is desired to effect control of the transfer spindle such that its
peripheral or surface speed is the same as the surface speed of the slow-down
conveyor 16.
Indexing movement of turret assembly 18 is effected to move
the transfer spindle to the position of winding spindle 20b. Driven rotation
of the winding spindle effects roll-formation as the web of material is
received from slow-down conveyor 16.
As noted above, the present apparatus includes a drive
arrangement for the winding spindle which is separate from the slow-down
conveyor drive 48, as well as separate from other drives of the apparatus.
This provides highly desirable versatility, pe~ g precise control of roll
formation. To this end, the drive arrangement includes a winding drive belt
64, and a winding drive motor 66 which effects driven movement of the
drive belt 64, and thus driven rotation of the winding spindle 20b. Idler 68
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- 13 -
m~int~in.c the desired level of tension in the winding drive belt 64. As will
be noted by the disposition of winding drive belt 64 relative to transfer drive
belt 56, indexing movement of each spindle moves each spindle out of driven
engagement with transfer drive belt 56, and into driven engagement with
winding drive belt 64. Again, this preferred arrangement obviates the need
for use of externally toothed timing belts, thus permitting the spindles to be
provided with non-toothed driven surfaces. Smooth, or knurled, drive
surfaces for the spindles can be employed.
Drive of the winding arrangement can be effected through the
use of a suitable electronic torque-controlled electric motor drive, such as a
servo-drive operated in torque mode. In a current embol1imPnt a Danfoss
Model 176B4000, DC 4 quadrant drive operating in torque mode, available
from Danfoss Corp., of Rockford, Illinois. The motor is a one-third
horsepower Bodine DC motor.
A control arrangement is preferably provided for measuring the
diameter of the roll of material being formed on the spindle 20b as the
spindle is driven by winding motor 66, with the control arrangement
preferably selectively varying the torque output of the drive motor in relation
to the ~i~meter of the roll of material being formed. To this end, nose roll
38 of slow-down conveyor 16 is mounted on an elongated pivot arm 70
which in turn is operatively connected to a slide control potentiometer 72.
For opeMtion, a potentiometer is employed for setting the starting level
torque of the motor 66, with the slide potentiometer 72 provided to measure
the ~ mPter of the roll being formed as the potentiometer is operated by
movement of pivot arm 70. As the roll being formed gets larger, the torque
level goes up from the additional input. The amount of influence that the
slide potentiometer 72 effects is adjusted by an associated potentiometer on
the operator panel.
Indexing movement of the turret assembly 18 is preferably
effected by a drive arrangement separate from the slow-down conveyor drive
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- 14-
48. In particular, an indexing motor 74 operates through a primary drive 75,
a jackshaft 76, and a secondary drive 78 to intermittently rotate turret 19 so
that spindles 20 are indexed in 90~ increments between their various
operating positions. In a current embodiment, an Indramat DKC servo-drive
5 module, with an Indramat style MKD070 motor, available from the Indramat
Division of the Rexroth Corporation, of Wood Dale, Illinois have been
employed. The DKC series drive allows pre-entered motion profiles to be
executed from simple logic level inputs. The notable advantage of using a
servo-motor is that no additional mechanical clamping of the turret 19 is
10 required when the turret is in its stopped position. The current control
system permits selection of one of three different turret index speeds via a
selector switch. The possible turret index speeds are llnlimite~l. The precise
positioning capabilities of the servo-drive assures that the in~ex~d position ofthe turret is exact, and repeated as the spindles are intermittently rotated.
- After completion of roll-formation on the winding spindle 20b,
the turret assembly 18 is indexed so that the completed roll is presen~ to
push-off palm 22. At this position, designated by spindle 20c, the completed
roll of material is axially displaced from the spindle by the push-off palm 22.
In order to facilitate such removal, the present apparatus is configured to
effect reverse rotation of the spindle 20c, thus acting to "unscrew" the
completed roll from the spindle. This driving of the spindle in a direction
opposite to that in which the spindle is rotating during roll-formation is
effected by spindle reversing motor 82 operating through spindle reversing
drive belt 84. As in the case of transfer drive belt 56 and winding drive belt
64, spindle reversing drive belt 84 is positioned to drivingly engage each
spindle as each spindle is moved into position of spindle 20c. The spindle
reversing motor 82 is operated intermittently, and for only a brief period of
time, in order to effect slight reverse rotation of the spindle 20c. Ordinarily,no more than several reverse rotations of the spindle 20c are required for
facilit~ting removal of the roll of material therefrom.
CA 0220~79~ 1997-0~-22
From the foregoing, it will be observed that numerous
modifirations and variations can be effected without departing from the true
spirit and scope of the novel concept of the present invention. It is to be
understood that no limitation with respect to the specific embodiment
S illustrated herein is intended or should be inferred. The disclosure is
inten-led to cover, by the appended claims, all such modifications as fall
within the scope of the claims.
